Clarifying representation of Neural Nerwork input for Chess Alpha Zero
For anyone wondering, I believe to have found the answer:

Yes, it will be an 8x8 plane where all the entries are the same, the number of moves (or mpves with no progress).

There are two repetitions planes (for each position from the most recent T=8 positions):
a) The first repetition plane will be a plane where all the entries are 1's if the position is being repeated for the first time. Else 0's.
b) The second repetition plane will be a plane where all the entries are 1's if the current position is being repeated for the second time. Else 0's.